Millar_2009_TaxCredits_USS_Chp13.pdf: This is a post-peer-review, pre-copy edited version of an extract/chapter published in 'Understanding Social Security: Issues for policy and practice' (2nd ed.). Details of the definitive published version and how to purchase it are available online at http://www.policypress.co.uk/display.asp?K=9781847421876;Millar_2009_TaxCredits_USS_Chp13.doc: This is a post-peer-review, pre-copy edited version of an extract/chapter published in 'Understanding Social Security: Issues for policy and practice' (2nd ed.). Details of the definitive published version and how to purchase it are available online at http://www.policypress.co.uk/display.asp?K=9781847421876